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3DR Radio, First Impressions

Posted by Mark Harrison on April 21, 2012 at 5:38pm

I'm thrilled to report that my radio kit arrived and it works well. Andreas is likewise happy with his kit.

Writeup here:

http://eastbay-rc.blogspot.com/2012/04/review-3dr-900mhz-radio.html

Fixing the air unit network id:

http://eastbay-rc.blogspot.com/2012/04/setting-network-address-on-3dr-air.html

Thanks 3DR, Tridge, and everybody else that worked in producing this unit!

3dr-radio

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Comments

Raymond Leach August 25, 2013 at 11:45pm

5v
Kevin Brown August 29, 2012 at 3:17pm

50 ohms
John Moore May 4, 2012 at 9:47pm

Ok I installed an ESC with a bigger, 5A SBEC. I have the option of outputting 5, 5.5, or 6V to the APM. Which voltage would be best?
John Moore May 1, 2012 at 9:49am

@Anderew Hmm, thanks for pointing that out. I hadn't noticed any problems but it looks like I should upgrade my ESC / BEC.

I tried another distance run this passed weekend trying to get to about a mile. The signal got pretty low at around 1500m but I didn't lose the connection. I was able to reduce the ground side noise by mounting my antenna on a tripod instead of the side of my truck bed which is where I had it before. I can post the tlog if you'd like to take a look. I was a little surprised that my 5.8 ghz video didn't degrade at that distance but telemetry did. Video is 600mw with the blue beam antenna set.
Developer

Andrew Tridgell April 29, 2012 at 6:34pm

@John,

I wonder if your ESC isn't quite handling the load? This is a graph of the 2560 CPU voltage for your flight:

as you can see, it drops below 4V for a while. That could cause quite a few problems. It really should be close to 5V the whole time.

Cheers, Tridge
John Moore April 28, 2012 at 7:21am

@Andrew

Im powering from a 3S LiPo through the ESC
Developer

Andrew Tridgell April 27, 2012 at 11:14pm

@John,

I checked with Michael, and he does take into account the sequence numbers of the RADIO packets, so that wasn't the explanation. The 5% loss is from the whole flight, and at times the loss is much higher which is a bit unexpected.

One thing I noticed is the HWSTATUS.Vcc voltage drops quite low at some points in the flight. How are your powering your APM?

Cheers, Tridge
Dennis April 27, 2012 at 8:04pm

@ Andrew Tridgell, Thanks for the clarification. I was trying to avoid getting the wrong antenna on the module then powering it up.

Alls ok though, I got the frequencies sorted and should maiden tomorrow.

All 4 radio's work as described, on the ground, and it looks like other than the three digit ID#, the default settings are spot on.

Thanks to all involved in this very usefull, and FUN project.

Dennis
John Moore April 27, 2012 at 7:37pm

@ Andrew

Thanks for looking at the logs. I never lost telemetry but I was a little worried about the link %'s. I used the Excel method Michael mentioned and charted the signal and noise and I consistently has more noise on the ground than in the air so Ill try adjusting that setup first.
Nicolas Larsen April 27, 2012 at 5:12am

*That was with dual 433mhz "air modules"